Antioxidant activity of enzymatic system of two different wheat (Triticum aestivum L.) cultivars growing under salt stress

Abstract

Soil salinity and semi-arid and arid climate of Pakistan is a major constraint in agriculture and predominantly in foodstuff production. It limits crop yield and use of land previously uncultivated. Wheat is moderately salt tolerant. A great variation was observed between and within the cultivars (genotypes: S-24 salt tolerant and DN-27 salt sensitive) in relationship to the choice of salinity level (control and treatments: in increment of 25 mol/m<sup>3</sup> NaCl/day to a final level of 80 and 160 mol/m<sup>3 </sup>NaCl into the nutrient solution) that will be used for screening purpose. Relative water content (RWC), membrane stability index and the activities of some antioxidant enzymes were determined after 20 and 40 days of salt stress exposure. As a result of activity enzymes, superoxide dismutase (SOD), peroxidase (POD) and catalase increased in S-24 with the increase of salt stress, while in DN-27 all the enzymes showed constant activity at all the stress levels. Meanwhile, relative water content and membrane stability index decrease the value as well as they increases the stress levels. It can be concluded that all three antioxidant enzymes were limiting factors for these genotypes and these reasons also led to the salt sensitivity in DN-27. Different selection methods should be applied to improve different traits in different conditions in wheat.

Differential Responses of Two Rice Varieties to Perchlorate Stress

“…It was suggested that the higher activities of CAT reduced H 2 O 2 levels in the cell and enhanced the stability of membranes and CO 2 fixation because several enzymes of the Calvin cycle in chloroplasts are very sensitive to H 2 O 2 . However, reports on the effect of environmental stress on CAT activity have been inconsistent [20,31,32]. In this study, both varieties show a significant increase and then followed by a decrease with the increased concentration of perchlorate.…”

“…Basu et al also demonstrated the activities of SOD were decreased in IR-29 (salt-sensitive) and PB (aromatic Pusa Basmati), whereas they were unaltered in Pokkali (salt-tolerant) when they were subjected to drought stress for two days [20]. But some studies show SOD activity will be enhanced when plants are subjected to environmental stresses [32,33]. However, the response of SOD activity to environmental stresses is reported to be dependent on stress intensity, species, and age of the plants exposed to stress [31,34,35].…”

“…Previous reports have shown that environmental stress such as salt stress [32], osmotic stress [33], and Cd [35] caused a significant increase in POD activities in different wheat or rice cultivars. The current results also showed perchlorate addition significantly increased POD activity at tillering stage, but there was no significant difference at heading stage.…”

Response of Salt-Stressed Wheat ( Triticum aestivum L.) to Potassium Humate Treatment and Potassium Silicate Foliar Application

“…This increase may be due to the synthesis of reactive oxygen species (ROS) (Baxter et al, 2014 andDietz et al, 2016). Antioxidant enzymes such as peroxidase and catalase are scavenging enzymes which regulate hydrogen peroxide (H 2 O 2 ) content, thus inhibiting the production of OH − radicals which produced from photorespiration and β-oxidation of fatty acids in organelles during metabolic processes (Rout &Shaw, 2001 andBhutta, 2011). Damaging of membranes fatty acids could produce small hydrocarbon fragments including MDA which is an important sign of membrane system injury (Masood et al, 2006 andMoussa, 2008).…”

Antioxidant capacity of oilseed rape (Brassica napus) in different soil types

“…The same situation is observed in the Zlatna genotype when it comes to SOD activity on both soil types and in all tested stages. By examining the effect of NaCl on the growth of wheat cultivars, Bhutta (2011) concluded that the scavenging of superoxide radicals by SOD had not been done perfectly. However, there are numerous studies that prove that this enzyme directly affects the reduction of oxidative damage during salt stress (Jalali-e-Emam et al, 2011;Muchate et al, 2016).…”